More information about factors that could affect our operating results is included under the captions "Risk Factors" and "Management's Discussion and Analysis of Financial Condition and Results of Operations" in our Annual Report on Form 10-K for the full year ended December 31, 2012, copies of which may be obtained by visiting our Investor Relations web site at http://investor.zynga.com or the SEC's web site at www.sec.gov . Undue reliance should not be placed on the forward-looking statements in this release, which are based on information available to us on the date hereof. There is no guarantee that the circumstances described in our forward-looking statements will occur. We assume no obligation to update such statements. The results we report in our Quarterly Report on Form 10-Q for the three months ended March 31, 2013 could differ from the preliminary results we have announced in this press release.
Non-GAAP Financial Measures:
We have provided in this release non-GAAP financial information including bookings, adjusted EBITDA, non-GAAP net income, non-GAAP EPS, free cash flow and adjusted EBITDA margin, as a supplement to the consolidated financial statements, which are prepared in accordance with generally accepted accounting principles ("GAAP"). Management uses these non-GAAP financial measures internally in analyzing our financial results to assess operational performance and liquidity. The presentation of this financial information is not intended to be considered in isolation or as a substitute for the financial information prepared in accordance with GAAP. We believe that both management and investors benefit from referring to these non-GAAP financial measures in assessing our performance and when planning, forecasting and analyzing future periods. We believe these non-GAAP financial measures are useful to investors because they allow for greater transparency with respect to key financial metrics we use in making operating decisions and because our investors and analysts use them to help assess the health of our business. We have provided reconciliations between our historical and second quarter 2013 outlook for non-GAAP financial measures to the most directly comparable GAAP financial measures. However, we have not provided reconciliation of our full year 2013 adjusted EBITDA margin (adjusted EBITDA as a percentage of bookings) outlook to a comparable operating income (loss) margin (operating income (loss) as a percentage of revenues) for full year 2013 because certain inputs necessary to accurately project revenue (including the projected mix of virtual goods sold in our games, the projected estimated average lives of durable virtual goods for our games and visibility into projected bookings) are not in our control and cannot be reasonably projected for the full year due to variability from period to period caused by changes in player behavior and other factors. As revenue is a necessary input to determine this comparable GAAP metric, we are not able to provide the reconciliation.